Philippa Eve or Felicity Winter?

Sorry to keep banging on with these names--we're still having a hard time deciding the name for our our second twin. VivienneGray (nn Vivi, Gray is a family name) is the likely candidate for twin 1's name, so now we're leaning toward either Philippa (nn Pippa/Pip) or Felicity (nn Fliss/Flick) for twin 2. Eve and Winter are likely for middles, though Eleanor is also still in the running. We decided want something longer for a first name since our last name is one syllable and it would sound funny with a one-syllable first as well.

What sort of feel does each name convey, and which goes best with VivienneGray?